The present invention relates to the manufacture of no-bake foundry binders and more particularly to a furan no-bake foundry binder containing bisphenol A tar (BPAT) filler. A "no-bake foundry binder", as used herein, means an organic chemical solution that is mixed into foundry sand and cured at ambient temperature by the action of an acid catalyst. The cured sand forms are used in metal casting operations.
Furfuryl alcohol is the key ingredient in furan no-bake foundry sand mold and core formulations. Furfuryl alcohol often is in short supply and is high in cost. Inexpensive fillers are used to reduce the cost of these formulations by replacing at least a fraction of the furfuryl alcohol. Such fillers must be compatible with the ingredients in the formulation. Most such fillers are by-products resulting from various industrial processes. Examples of such traditional fillers include residues from the ozone oxidation production of azeleic acid; by-products (mixed esters) from the production of terephthalic acid and its esters; lignins and lignosulfonates from the paper industry; and various rosins from the forest industry.
Heretofore, for example, bisphenol A tar has been proposed for use in phenolic-based, heat-cured foundry shell resin formulations (British Pat. No. 2,271,357).